Rapid manufacture of low-seed CAR-T cells in a GMP-grade hollow-fiber bioreactor platform

Both quality of product and rapidity of manufacture are critical parameters if ex vivo manufacturing of autologous chimeric antigen receptor T cell (CAR-T) therapies is to reach its full potential. The Quantum Flex Cell Expansion System from Terumo Blood and Cell Technologies (Terumo BCT), a hollow-fiber bioreactor platform, is one of several cell expansion systems available to cell and gene therapy manufacturers to generate such cells in a GMP-compliant manner. In this study, the dynamic range of the Quantum Flex platform to expand CD19 CAR-T cells from variable quantities of starting material was investigated. Reflecting the industry's utilization of contract development manufacturing organizations (CDMOs) for accelerating clinical timelines, Terumo Blood and Cell Technologies performed a technology transfer of application protocols for study execution. Four different amounts of starting material (1, 3, 6 and 15 million cells) were expanded on Quantum Flex, using a unique donor's cells for each run. In this study, CAR-T cells were created using commercially obtained T cells and an anti-CD19 CAR-T lentiviral construct. The resultant heterogenous cell populations were expanded for 7 days in the functionally closed bioreactor platform. Expansion kinetics for all 4 starting material amounts were remarkedly similar, resulting in a 150- to 200-fold increase in cell numbers. This allowed for a study maximum of 2.6 billion cells from loading 15 million cells. Viability remained high throughout the expansion process with >93% for all 4 donors at harvest. To complete the manufacturing cycle, the automated and functionally closed Finia Fill and Finish System (Terumo Blood and Cell Technologies, Lakewood, CO) was used to formulate the cells for cryopreservation. Postprocedure analysis for potency and cytotoxicity demonstrated the production of efficacious cells. With this range of starting numbers, the platform is relevant to adult, pediatric and compassionate CAR-T expansion dosing. Today, several platforms are available to achieve sufficient cell yields for therapeutic applications of CAR-T, and awareness of the capabilities, pros and cons of each platform is critical to drive progress.